I am planning a trip to Utah in September, and I'm concerned about the height restriction going through the tunnel at Zion NP. I checked the specs for a Winnebago Journey, and it says it measures 12'. The tunnel restricts anything over 13'1". We have a satellite dome on our roof. My husband was thinking we could dump the air out of the shocks, but I called the park and they said the tunnel is close to a mile long. That would be a very bumpy mile. Has anyone else with a diesel pusher and satellite dome ever gone through the tunnel? (SAFELY ? I don't mind going back around, but thought I'd ask. Additionally, has anyone ever traveled UT-21 from Great Basin National Park down to Cedar City, UT in a motorhome?